Ski binding



Aug. A B LANZ sx1 BINDING Filed July 50. 1942 m\ mmm- ILL E if@ UL 4l nl .9 n 050 Patented Aug'. 21, 1945 UNITED STATES PATENT- oEFicE sx1 BINDING Adrian Berchtold Lanz, Zurich, Switzerland Application July 30, 1942, Serial No. `452,940 In vSwitzerland May 18, 1942 3 Claims. (Cl. 28o-11.35)

The cause of nearly all fractured legs and sprained knees and ankles in skiingis the fact that, when the skier falls, his foot, which is held fast in the toe clamp of the binding, is often forced into positions beyond the natural range of the foot and knee Joints or beyond the power of resistance of the leg. 'Ihis overstrain on the resistance oi' the leg or the knee is mainly due to the rigidity of the binding in respect of a turning of the foot about a vertical axis. A fall caused by crossing ofthe skis results in at least one or even more violent twists of the feet, since the binding cannot yield in the required direction.

The present invention aims at obviating this evil by providing the ski with a toe binding which is capable of turning in the horizontal plane, for

instance, about a vertical axis. When a certain resistance is overcome the toe clamp can now swivel round into a position transverse to the ski itself.

The iitting of the toe clamp is most advantageously carried out in such a, way that, when the weightof the skier is on the binding plate, the resistance of the toe clamp to torsion is so great that all turns and swings can be executed without any danger of swivelling the binding, while, when there is no weight on the ski, which is always the case at the moment of a i'all, the resistance of the toe clamp of binding to torsion, which it is necessary to overcome, is never greater than the resistance of the leg. As soon as a certain tensile strain is exerted by the foot held in the toe clamp, the binding can be swivelled on the axis of the toe clamp without resistance. The latter case frequently presents itself when a ski sticks in wet snow.

A possible form of execution for the object of the invention is shown by way of example in the drawing. This illustrates:

. Fig. 1 a longitudinal section of the portion of the ski to which the binding is afxed, with the toe clamp in. its normal position,

Fig. 2 the same longitudinal section after the release oi the spring check,

Fig. 3 a horizontal section of Fig. 1, and

Fig. 4 a detailed variant.

The example of a possible form of execution of the ski binding shown is provided with a round binding plate I, which carries the ski binding and is screwed on to the ski 2. This binding plate has on its under-side a central pivot socket 3 which fits into a corresponding hole bored into the ski. On its upper side binding plate I has a collar I on the same axis as socket 3 but of smaller diameter. This collar forms the axis of a turntable 5 which can turn on the binding plate I and which, together with an easily removable vcovering plate t attached to it, forms the base of the toe clamp into which fits one clamp jaw l on each side, this jaw being adjustable by means of teeth l or capable of being xed in the desired position by means of screws 3. l' is the guide rim of turntable 5 which overlaps the rim of the binding plate. I 0 designates the binding attached to the jaws 'I of the toe clamp. The normal position of jaws 1 of the toe clamp is arrived at by means of a checking device which yields at a certain pressure. This check is formed by indentations II provided in the under-side of turntable 5 and by catches I2 provided on binding plate I which engage indentations II. Bolt Il, with its head plate I3, is positioned in collar 4, and the inside end of this bolt can be screwed into a bush I5 by means of athread I4'. The bush I5 can be moved lengthwise in pivot socket 3 and is secured against twisting by peg I5 introduced into a lengthwise slit I6 in socket 3. By means of a pressure spring I'I, which presses at one end against bush I5 and at the other against the step 3a of collar 3, the head plate I3 oi' the bolt I3 is pressed down against its seat sunk in the base of toe clamp I, 6. It follows that toe clamp base Il, 6 can only rise from the binding plate I counter to the pressure action of spring Il, and this rising releases the checking device. By tightening bolt I4 to a greater or less degree the tension of spring I'I can be adjusted between 20 and 30kgs. approx. When the weight of the body is on the ski, the resistance to the swivelling of toe clamp t. t which has to be overcome in order to release the check is so great that the device remains securely engaged even when the most diverse turns and swings are executed. When the weight is removed or almost completely removed from the ski, as occurs in the case of a fall, the checking device yields to the strong torsion of the foot in the toe clamp before the powers oi resistance of the leg are exceeded. If during a fall a tensile force counter to the pressure of spring I'I is exerted by the foot on the toe clamp, then the release oi theeheck is possible with very slight resistance to torsion. By means of the swivelling of the toe clamp, i. e. ofthe binding, made possible by the overcoming of a certain resistance as described above, the danger of breaking a leg or straining a leg joint in a fall is greatly diminished.

In the variant shown in Fig. 4 turntable 5 is equipped with a rim 5" which bends inwards and which, while leaving a certain margin of play,

grips a projecting rim I' of the binding plate. so that the lifting movement of the toe clamp l, l from the binding plate I, which is necessary for the release of the checking device. is limited by rim I".

It will be obvious to those skilled in the art that various changes may be made in this invention without departing from the spirit thereof, and the invention is not limited to what is shown in the drawing and described in the specification,

but only as indicated in the appended claims.

I claim:

l. A ski binding comprising in combination with a ski. a binding plate rigidly attached to the ski, a toe clamp having a base plate movably mounted on the binding plate and adapted for rotation in a horizontal plane, means for normally resisting rotary movements of. the base plate and a spring for forcing the base plate into holding engagement with the binding plate.

2. A ski binding comprising in combination with a ski, a binding plate rigidly attached to the ski, a toe clamp having a base plate movably mounted on the binding plate and adapted for rotation in a horizontal plane, means for normally resisting 25 ski, a toe clamp having a base plate movably mounted on the binding plate and adapted for rotation 'in a horizontal plane, means for normally resisting rotary movements of the base plate, a spring for forcing the base plate into holding engagement with the binding plate, the ski having an opening therein beneath the binding plate, a tubular b'oss depending from the binding plate and disposed in said opening, said spring being coiled and located in said tubular boss. a headed screw passing downwardly through said plates and coiled spring and terminating in said boss and a bushing in the boss into which the lower end of the screw is threaded, the headed Y bushing being longitudinally movable in the boss 

